About 45,000 employees, members of the Communications Workers of America (CWA) and the International Brotherhood of Electrical Workers (IBEW) could not find common ground in negotiations, and the union leaders called a strike, which began Sunday at 6 AM, according to NJ.com.

CWA workers have claimed that Verizon wanted $1 billion in concessions from existing union contracts, specifically looking to tie pay increases to performance review and require union workers to contribute to health-plan premiums. The company is also seeking to freeze pensions at the end of the year, eliminate the sickness and death benefit program, cut in half the sickness disability benefits from 52 weeks to 26 weeks and reduce sick time, according to an IBEW memo obtained by NJ.com.

In response, Verizon said that it had trained tens of thousands of management workers, retirees and others to fill the roles of the striking workers. "We are confident that we have the talent and resources in place to meet the needs and demands of our customers," said Marc C. Reed, Verizon's executive vice-president of human resources, in a statement on Sunday.

Verizon said then that customer service would remain unaffected; Verizon Wireless will as well.

On Monday, however, Verizon said that it had repaired 12 acts of sabotage to its facilities, beginning Saturday. The "criminal incidents of sabotage," according to Verizon, affected phone, Internet, and TV service to Maryland, Massachusetts, New Jersey, and New York. Verizon stopped short of directly accusing its striking workers of the alleged sabotage, however.

The incidents involved ten instances of fiber-optic lines being cut, stolen electronic equipment in Cedar Grove, New Jersey, and an incident due to tampering with a heating system at a central office in Manhattan. The Verizon team completed more than 75 percent of repair commitments on Sunday, it said.

"These acts of sabotage are reprehensible," said Verizon Chief Security Officer Mike Mason, in a statement. "In addition to inconveniencing our customers, these deliberate disruptions of our network have affected hospitals, paramedics, fire fighters, law enforcement and other first responders. Verizon is working closely with local authorities to investigate these sabotage incidents, and identify and prosecute those responsible to the fullest extent of the law. And we will not hesitate to terminate any employee who may be involved in these acts."

Verizon said it would offer a reward of $50,000 for information leading to the arrest and prosecution of individuals that intentionally damage Verizon cables or facilities or cause or attempt to cause physical injury to any Verizon employee or contractor.

Mason also said that striking workers had also, in some instances, prevented the company from accessing tools it needed to serve its customers.

Union officials were not immediately available for comment. In a statement from CWA communications director Candice Johnson, the CWA blamed Verizon for cancelling scheduled negotiations.

"Verizon's concession demands would strip away the middle class standard of living that workers have gained through bargaining over the past 50 years," Jonson said in a statement.

This article, written by Mark Hachman, originally appeared on PCMag.com and is republished on Gear Live with the permission of Ziff Davis, Inc.